标题：Helical nanostructures self-assembled from optically active phthalocyanine derivatives bearing four optically active binaphthyl moieties: Effect of metal-ligand coordination on the morphology, dimension, and helical pitch of self-assembled nanostructures
作者：Wu, L.;Wang, Q.;Lu, J.;Bian, Y.;Jiang, J.;Zhang, X.
作者机构：[Wu, L] Department of Chemistry, Shandong University, Jinan 250100, China;[ Wang, Q] Department of Chemistry, Shandong University, Jinan 250100, China 更多
通讯作者地址：[Jiang, JZ]Shandong Univ, Dept Chem, Jinan 250100, Peoples R China.
来源：Langmuir: The ACS Journal of Surfaces and Colloids
摘要：(R)- and (S)-Enantiomers of optically active metal free tetrakis[11,12:13,14-di(1′,2′-naphtho)-1,4,7,10,15, 18-hexaoxacycloeicosa-2,11,13-trieno]-phthalocyanine and their zinc complexes, (R)- and (S)-H_2Pc (1) and (R)- and (S)-ZnPc (2), were prepared from the tetramerization of corresponding phthalonitriles, (R)- and (S)-2,3-(4′,5′-dicyanobenzo)-11,12:13,14-di(1′, 2′-naphtho)-1,4,7,10,15,18-hexaoxacycloeicosa-2,11,13-triene, in the absence and presence of Zn(OAc)_22H_2O template, respectively, promoted by organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Their self-assembly behavior in the absence and presence of 4,4′-bipyridine has been comparatively investigated by electronic absorption and circular dichroism (CD) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) technique, and X-ray photoelectron spectroscopy (XPS). The metal free phthalocyanine self-assembles into highly ordered fibrous nanostructures (ca. 3 μm length, 70 nm width, and 125 nm helical pitch) with left-handed and right-handed helicity for (R)-1 and (S)-1, respectively, through the hierarchical manner via one-dimensional helices with chirality determined by the optically active binaphthyl side chains. In contrast, self-assembly of the phthalocyaninato zinc analogue leads to the formation of nanoparticles. However, in the presence of 4,4′-bipyridine, additionally formed metal-ligand Zn-N_(4,4′-bipyridine) coordination bonds between the nitrogen atoms of additive 4,4′-bipyridine molecule and the zinc center of (R)- and (S)-2 molecules together with π-π interaction and chiral discrimination of chiral side chains induce a right-handed and left-handed helical arrangement in a stack of (R)- and (S)-2 molecules, respectively, which further hierarchically packs into highly ordered fibrous nanostructures of average tens of micrometers in length, 30 nm width, and 106 nm helical pitch with the same helicity to the stack, revealing the effect